1. Field of the Invention
The present invention relates to an irrigator with an oscillating arm.
2. Related Art and Other Considerations
Irrigators for gardening are known that comprise a hollow arm provided with a longitudinal succession of holes for the passage of water that, issuing from a water supply point, flows inside the arm itself. The latter is made to oscillate round its own axis, for example by means of a unit with a turbine and means for transforming motion from rotatory to oscillatory, by the pressure of the water, so as to irrigate alternately portions of land located on opposite sides with respect to the irrigator. The total irrigated land area has a width corresponding to the length of the oscillating arm, and a length equal to twice the maximum distance covered by the jets of water issuing from the holes.
Irrigators are also known wherein the width of the irrigated area can be modulated by varying the length of the oscillating arm, by means of plugs, sliding along the same arm to cover up a desired number of holes, placed at the end of the arm.
The total irrigated land area depends, however, not only on the length of the oscillating arm, but also on the length of the jet issuing from the individual holes, that is essentially on the pressure of the water inside the arm. Such pressure is linked to the number of holes utilized in the oscillating arm, so that in arms of greater length and thus with more holes, diminishing the pressure of water inside the arm, would consequently diminish the length of the jet issuing from the holes, and no benefit in terms of the irrigated area would thus be obtained. For this reason in irrigators produced normally the oscillating arms do not have more than 18 holes.
A similar problem would be exhibited if, for an equal length of the oscillating arm, the distance between the holes were to be diminished so as to have a greater fineness in the distribution of the water: as for the previous case, the increase in the number of holes would determine a drop in the pressure of the water and thus a reduction in the length of the jet issuing from the holes themselves. If the pressure of water were to be reduced excessively, the irrigator would no longer be capable of carrying out its functions properly, since the area of irrigated land would be reduced to a small region surrounding the irrigator itself.
In view of the described state of the art, the object of the present invention is to provide an irrigator with an oscillating arm wherein the arm itself can have a high number of holes, so that it is possible to provide arms that are longer and/or with holes very close to one another, without it being subject to problems of drops of pressure of water and thus of a reduction in the area that can be irrigated.